Shop Hydro Test of Carbon steel pipes according to APi 5L specification

[MatSci1254]

Hi,

Need your help to understand the specification requirment. API specification requiers Hydro test on pipes at pressure calcuated by equation 2St/D with S value equal to 60% of SMSY, test duration specified is 5 seconds. I trying to find out why the test duration is 5 seconds? Does increasing the test duration to 10 seconds is advantegious in any way? I have come across a project specification in which the test duration is 10 seconds. what these extra 5 seconds are for?

Apprecite you response


Regards
SMA

Regards
MatSci1254

 

[LittleInch]

API 5L has different min SMYS limits ofr different grades of pipe and sizes so it's not a standard 60%.

Also I couldn't find 5 seoncds listed anywhere in API 5L. This is a customer requirement, but most mills do 5 or 10 seconds as if it hasn't failed by then then it won't and they just want to gewt the testing over with as afast as possible.

the method of testing is pretty brutal in the mill so adding 10 seconds just gives a bit more time for the inspectors to work out if there is a hole on the pipe or not whislt the water is being injected in faster than it's coming out....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way